4runner_guy

I'm still learning a lot on my first truck, so forgive me for the noob questions. I have been searching on the site and googling for some solutions to get my heater for my 88' 4Runner to work. It blows out just fine but has no hot air coming out of it. I ran into a few threads that had a little info on flushing but it seems rather hard for me since I am more of a "visual" learner. So pictures are a great source but when some of the threads are really old, the pics seem to have been deleted so it makes it hard to understand what the info is trying to tell me. So forgive me for having a bit of disability on comprehending the info on the forums.
So far from my recent check outs on "what" could be the solution has not been successful: checking the relays (good), Fuse (good), hose (good), climate controls-cables to 3 controls, (good), radiator flush, replacing T-stat, but have not done a flush on the heater core (?). The hoses, which connects to the firewall and to the heater core are warm (The hose close to the driver side) but the passenger side is cold.
The trucks A/C doesn't function too. So if anyone here would kindly please lead me to the next direction on what to do, it would greatly be appreciated. Thanks in advance.

dhall50

Since 1 side is warm and the other is cold i would guess there is a plug. I would remove both heater core hoses (Be careful not to bend or crack the heater core pipes) and put a hose up to one end of the heater core(Pipes going into the firewall) and try to flush debris out this way. If this doesn't work it is time to swap out the heater core witch is a major PIA.

sb5walker

https://www.yotatech.com/forums/f116...cement-124222/

4runner_guy

Does it matter which hose I place the garden hose into? The hose close to the passenger side is cold while the one closer to the drive side is warm. So I just insert it (garden hose) into one of the pipes of the heater core along the firewall and moderately hose it down with water until I see debris come out from the other pipe correct?

Yeah, I saw this thread, I was looking into flushing the heater core instead before I go digging through to pull it out. Thanks though.

bicklebok

Here, this thread should help you some on the flush. It's a relatively new thread.
https://www.yotatech.com/forums/f116...es-not-224593/

4runner_guy

Lol, I was follwing this thread earlier too! Glad you brought this back up to my attention! Thanks.

4runner_guy

So after about an hour of flushing and large debris coming out of the pipes, I reinstalled everything back and topped off the radiator. I started the truck up and re-topped the radiator with coolant and watched the air bubbles come out. Once I was done with that, I went into the cabin to fire up the heater....well, I got a little bit of heat but not what I was expecting...then it hit me, around my peripheral, I noticed a shimmering light on the passenger side floor and noticed that the passenger side was flooded with water and LOTS of sunflower seeds. Does this mean that my heater core is bad and has a leak? I followed the procedures from the threads I read so I couldn't have messed up. I'm guessing that if I have a leak, it could cause the heater in the truck to not function correctly, thus explaining the poor heat performance. I guess it's time for a new heater core, used from the junk or new from the dealer? What do you guys think?

dhall50

If you are sure the water didnt get in there from the hose then it sounds like you need to replace it. The seeds are odd though and make me wonder if a mouse has been storing his belongings around the heater core. As you mention this i remembered that when I replaced my core kits of junk had surrounded the actual core preventing air from flowing through part of it. You need to buy a new one. They dont cost much and you dont want to risk installing a bad one because it is a major PIA!

4runner_guy

What are the price range of a new heater core?

shaeff

If the heatercore is leaking, flushing will just make it worse. If your heatercore is NOT leaking, and you have no heat, first check the heater valve on the firewall to make sure it's opening completely. Next, backflush (always backflush- the reverse of the coolant flow) the heatercore, that way you're not trying to force the blockage through the core.

Flushing the core always increases the chance of springing a leak, so don't use much pressure.

If none of that works, you could try some vinegar mixed in the water used to flush, but again, that will increase your chances of springing a leak.

That link above is from when my heatercore began to leak, fogging up my windshield and the sweet maple syrupy smell from the vents. Flush your cooling system every two years.+

4runner_guy

Here what the valve looks like when it's open (Hot settings)?

And when it's closed (Cold settings):

Is this what it's suppose to look like?